<html>
<head>
    <style>
        table{table-layout: fixed;width:800px;background-color: #CCC;}
    </style>
</head>
<body>
    <table  >
        <tr>
            <td width="50">50px</td>
            <td width="50%">50% aaaaaaabbbbbbbccccccc</td>
            <td width="50%">50% aaaaaaabbbbbbbccccccc</td>
            <td width="50">50px</td>
            <td width="100">100px</td>
        </tr>
        <tr>
            <td>50px</td>
            <td>50% aaaaaaabbbbbbbccccccc</td>
            <td>50% aaaaaaabbbbbbbccccccc</td>
            <td>50px</td>
            <td>100px</td>
        </tr>
    </table>
</body>
</html>